Machining the angle mount- Removing excess material

The first step of machining the angle mount was to remove most of the material from the Upper Arm.

I did this by first slitting as deep as I could into the arm, first, parallel to the blade mount, and then across it. Since the slitting saw will only enter 2″ deep, you can’t remove more than a 2″ strip at once. This means you will have to remove material in multiple passes. The process would be infinitely easier with a horizontal mill, but we didn’t have one, so I had to make due.

After this first pass, I had to mag-drill around the section that the saw couldn’t reach so I could remove the large section.

After that, I continued slitting bits at a time, and removing material by mag-drilling it out. If the slug was still attached to a bit of steel, I would pry and hit it with a hammer to remove it.

After the first pass, I machined down a stripe so the cap on the slitting saw wouldn’t interfere, and I could continue cutting at the same height.

Space machined down for the cap

See the gallery below for a series of how all the material was removed.

Advertisements

Waiting on the Half-Moons

The Upper angle blade and the half-moons

Progress is halted on machining the angle mounts, because I don’t believe the blade and the half-moons match.

The half moons (see this video for visuals) are what push against the upper angle blade. They allow it to rotate throughout the cut to compensate for the rotation of the upper arm. This allows the blade to be parallel to the angle being sheared at all times during the cut.

The angle blade assembly for a smaller Piranha machine

From the video linked above, you can see that in the Piranha version (this is for a smaller machine), the half moons are only slightly shorter than the blade itself. This means the force is being distributed throughout most of the blade.

With the ones I got sent from Piranha, the half moons are much smaller in comparison with the blade, and they are thinner as well.

Side view of the half-moons and the angle blade

It would make sense for them to be the same thickness, and closer to the same overall length. My solution is to order the Half-Moon’s for the next size up machine.

There is a chance that the blade I was sent from the blade manufacturer was the wrong dimensions. The other possibility is that Piranha sent me the wrong parts. They sent me the wrong parts initially, but I caught it on the invoice, and was able to return them. They supposedly sent me the new ones, which I received last week, but I still believe they are the wrong size.

On the new invoice, it says the part is the “P-70/P-90 Angle Knife Block”. This would imply that the P-70 uses the same part. However, the capacity on the P70 is only for 5x5x1/2″ angle, whereas the capacity for the P90 is 6x6x5/8″. A piranha representative informed me that the P90 does have a larger blade. So, it follows that the P90 would have a different set of Half-Moons.

Also, the P90 and the P120 have the same angle capacity, so it would make sense for them to have the same half-moons.

So, I will order the parts for the P120 and suck up the $100 it will cost.

If the part is the same size, I will assume it is the correct size and machine it for the smaller half moons. If not, I’ll sure be glad I ordered the new ones!

If the moons are too small, what could happen is it could compress the part of the upper arm which pushes on it, loosening up the mechanism.

I had initially planned on finishing all the machining on the upper arm in San Diego, but now will finish in Missouri.

Overall update

I’m in the final push for getting the ironworker shipped to Factor e Farm. I put up a Uship auction for shipping it:http://www.uship.com/shipment/Ironworker-Machine–a-few-small-boxes/607441616/

The guy who is winning now wants to ship it tomorrow afternoon! I may need to choose someone else, as I might not have the machining done by then.

Basically, that means a very long day for today, possibly an all nighter.

I’ve got lots of pictures and videos to put up, but that’s gonna wait until my final push.

Machining the upper flat blade mount

I’m currently machining the blade mounts. I expect they should be done by tuesday.

The flat blade wasn’t bad to machine, except for the fact that I had to weld extra material on due to the innaccuracy of the slitting saw. Welded material is machinable, but it is much more difficult to machine than regular steel. I found the fly cutter worked horribly on the welded material, and that I had to use an endmill instead. Overall, it took about 6 hours to fix. First I welded it up, then I machined it down.

To check the height on the mount, I used the blades I ordered. When the machine is assembled, there needs to be .007″ to .010″ clearance between blades. I machined the mount deep enough so that the blades were just barely under the thickness of the arm. I may need to machine more later, but the lower mount can be machined instead of the entire arm.

For now, it is better that not enough material has been removed vs. too much. If I remove too much, I will need to shim the blades to get the proper clearance. While this is doable, it would make for a lower quality machine which is more likely to get out of adjustment.

Before I call the job finished, I need to figure a way to remove material from the upper edge. No milling bit is perfectly square, so the bit of material left on the upper edge is preventing the blades from sitting square on both surfaces. I may just use a dremel and grind/cut away a bit of the edge. I’ll post a vid when I figure it out.

My trip to the moon

A few years ago, I had this boyfriend who dreamed of going to the moon. It wasn’t really an active dream, as he was doing nothing whatsoever to pursue it. He would just mention it every now and then, thinking he hadn’t told me about it yet. It seemed to haunt him though, and it came up a lot in our short romance.

Whenever the moon came up in conversation, he’d look off into the distance and, in a tone which almost sounded hurt, say something like, “If someone told me I could go to the moon, but that it would be a one way trip, and I’d never come home again, I’d do it. Just to be there once.”

I thought it was silly, and alarming, at the time. How could you leave everything you know and love for something as trivial as Zero G, and a whole lot of monotonous rock? He, who was so potent, and young, and who had so much to live for. What could the moon possibly hold to take him away from all of that? That could take him away from me?

I think I finally understand his “give everything up for it” kind of dream; I now have one of my own. Although I must say, I find it much more compelling than something so trivial as a visit to the moon.

I try not to pine for things which are impossible, as my dream very much is; there are far too many things which are tangible to focus on. But now and then, I let myself slip into it.

I’d give up my body, my self, all the knowledge I possess for it. I frequently find myself wishing I were there, wondering if there’s any way I could conjure myself up a substitute for it in modern day time. Knowing that, given the advance of technology, and economy, and the current political state of California, there’s virtually no way of recreating that era.

I’d work with the crane crew in Enniss’ golden age. I’d be doing the ironworks; fabricating beams, stairs, plates, all kinds of things. And then, I’d ride with the crew to LA and set it up. We would be doing building after building, cell phone towers galore, torching up the worlds biggest helium tank…

I hear so many stories of that age; from my grandfather, from Uncle Wade, from Jimmy, from Russ, from Uncle Chad. It’s a world I escape into sometimes. Imagining what it was like is my guilty pleasure; it gives me an incredible high, but at the same time, I know those days are gone, and I end my nostalgia for their experiences with a sadness of my own.

Even if I’d been born 7 years earlier, I could have been on the tail end of it.

Why that age passed, there isn’t really a clear answer for. Grandad shrunk the business down from about 200 employees down to 1/2 of that at one point, simply because the business wasn’t as efficient, or as profitable, with that many employees. Of course we can blame the economy, as seems to be the trend these days, but I find that to be a bad excuse; there are many construction companies which pulled thru the down-turn. And besides, we sold off the crane division in 2001, far before the recessions. The selling of the cranes is a clear turning point.

To be continued…

Slitting saw inaccuracies

Unfortunately, the slitting saw wasn’t as accurate as I’d thought it would be. Once I’d removed the on the flat blade material, I noticed the variation of about 1/16″. The surface needs to be perfectly flat and recessed 2.005+_.005″. This gives the blades the proper clearance to do a perfect shear.

I had thought the saw would be accurate to 1/32″, so that’s where I made the cut. However, I was off a bit on the measurement and there was significant variation. So, the middle of the cut was about 1/32″ high, and the sides were about 1/32″ low. I will need to weld up the low spots and machine it to size. To accurately find the high’s and lows, I used a fly cutter to take it all to the correct height. where it show’s it’s low, I will weld.

Since the high spot was in the middle, It tells me that the variation couldn’t have been caused by mounting the piece crooked.

This is a very time-consuming error. Machining is something in which you pay heavily for your sins….

I’ll update this with pictures tonight or tomorrow morning.

Removing the slitted material

After the slits were made, I had to mag-drill some material away to remove the sections I cut.

For each blade, first I used a combo square to mark how far the cuts went in. Since the blade has a big radius, it won’t cut all the way into the corners. Here’s a vid explaining that:

To remove material from the flat blade, first I drilled a large (1.75″ DIA) hole at each side of the mount. Then I pried away the material in the middle. After that, I mag-drilled a series of smaller holes and used a cut-off blade to remove the remaining material that I could. When I’d removed all I could that way, I milled away the remaining material.

Here’s a video series explaining how I did it.



For the angle mount, it was a similar process.